Polyolefins stabilized with nickel or cobalt complexes of halogenated mono or dithio beta diketones

ABSTRACT

Polyolefin resin compositions having improved ultra violet and thermal stability properties are obtained by incorporating with the resins small amounts of a cobalt or nickel complex of a partially halogenated mono or dithio beta diketone.

United States Patent [1 1 Guillory et al.

[ Dec. 24, 1974 POLYOLEFINS STABILIZED WITH NICKEL OR COBALT COMPLEXES OF HALOGENATED MONO OR DITHIO BETA DIKETONES [75] Inventors: Jack P. Guillory, Bartlesville, Okla.;

Ronald D. Mathis, Taylors, SC.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

22 Filed: Oct.31,1973 211 Appl. No.: 411,455

[56] References Cited UNITED STATES PATENTS 3,692,738 9/1972 Mathis et al. 260/4585 3,763,092 i0/l973 Mathis et al 260/4575 Primary ExaminerV. P. Hoke" Attorney, Agent, or FirmNeuman, Williams, Anderson & Olson [57] ABSTRACT Polyolefin resin compositions having improved ultra violet and thermal stability properties are obtained by incorporating with the resins small amounts of a cobalt or nickel complex of a partially halogenated mono or dithio beta diketone.

5 Claims, No Drawings POLYOLEFINS STABILIZED WITH NICKEL OR COBALT COMPLEXES OF HALOGENATED MONO OR DITIIIO BETA DIKETONES stabilizers. Many of the proposed additives, while satis-.

factory in one or more respects, exhibit certain disadvantages such as less than complete compatibility with the resins or a tendency to adversely affect the color of the products.

It is a principal object of this invention to provide polyolefin compositions containing small amounts of stabilizing additives with the resulting composition having greatly improved ultraviolet radiation stability.

The foregoing object as well as others is accomplishcd by incorporating with a polyolefin a relatively small stabilizing amount of a nickel or cobalt complex of a mono or dithio-beta diketone of the formula:

wherein:

Z oxygen or sulfur,

X fluorine, chlorine, bromine or iodine, and

R is a hydrocarbyl radical selected from alkyl, aryl and cycloalkyl radicals and combinations thereof such as alkaryl, aralkyl, alkylcycloalkyl and the like containing from l to 18 carbon atoms, more preferably l to 12 carbon atoms.

Exemplary mono and dithio-beta diketones* include:

Nickel and cobalt derivatives of the above mono and dithio-beta diketones are formed by reacting solutions of an appropriate metal compound (i.e. nickel acetate. cobaltous acetate, etc.) and the diketone and finally isolating the product by filtering, extraction, etc. Solvents in which both reactants are soluble, such as alcohol, are preferable. A two-phase solvent system may also be used. The diketone is dissolved in an organic solvent, such as an ether, and the metal compound dis solved in water. The two solvent phases are shaken or stirred together vigorously, the reaction occurring interfacially. The product is isolated from the organic phase by evaporation of the solvent. Further purification can be accomplished by normal methods. Examples of the nickel and cobalt derivatives include: bis( 1 1,l-trifluoro-7-methyl-4-thiolooct-3-en-2- one)nickel(ll), bis( 1 ,l ,l-trifluoro-4-thiolopent-3-en-2- one)cobalt(ll), bis( 1,1,l-trichloro-2,4-hexanedithionato)nickel(ll), bis( 1 ,l,l-tribromo-2,4- dodecanedithionato)nickel(ll),' bis( 1 ,l ,l-trifluoro-4- phenyl-4-thiolobut-3-en-2-one)cobalt(ll), bis( 1,1 ,ltrifluoro-4-methylcyclohexyl-4-thiolohept-3-en-2- one)nickel(ll) and the like.

The discovery of this invention is generally applicable to the stabilization of homopolymers and copolymers of l-olefins containing from 2 to 8 carbon atoms per molecule. Examples of such include polyethylene, polypropylene, poly( l -butene poly(4-methylpentene-l propylene/ethylene copolymers, ethylene/l-butene copolymers, ethylene/l-hexene copolymers, ethylene/l-octene copolymers and the like and mixtures thereof. When the polyolefin is polypropylene, it is preferable to include in the composition a minor amount of an antioxidant to provide heat stabil ity during processing.

Suitable antioxidants (heat stabilizers) to admix with the compositions are hindered phenols selected from the group consisting of 2,6-di-t-butyl-4-methylphenol,

tetrakis-[methylene(3 ,5 -di-t-butyl-4-hydroxyhydrocinnamate lmethane, octadecyll 3( 3 ,5-di-t-butyl-4- hydroxyphenyl)]propionate, di-n-octadecyl(3,5-di-tbutyl-4-hydroxybenzyl)phosphonate, l,3,5-trimethyl- 1, 1, 1 trifluoro-7-methyl-4-thioxo- 2-oxooctane o s n H cc1 cca ccr1 t i l CF3CCH2C(CH2)11CH3 s 6) o s r v H N CF3CCH2C CH3 decane 0 ll CF CCH CCH CH I 1 1, 1- trifluorc 2 4-hexanedithione l 1 1- trifluoro- 2 4-nonanedithione 3 4 O S ll ll CF CCH CCH l l l-trifluoro--pheny1-4-thioxo-2- oxopentane O S H II CBr CCH CCH C1-1 CH 1 1 l-tribromo-4-thioxo- 2-oxoheptane These compounds, although shown in ketonic form, also may exist in equilibrium with the corresponding enolic form.

2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)-benzene, 2,- minutes. The temperature of the reaction mixture was 2-methylenebis(6-t-butyl-4-methylphenol) and the maintained at 50 to -65 C. during the addition and like. then allowed to warm to room temperature over a 4 The cobalt or nickel ultraviolet stabilizers ar mhour period. The orange solution was then allowed to ployed in the polyolefin compositions in accordance stand at C. under a nitrogen atmosphere for 3 days. with this invention in relatively small amounts, ranging The reaction mixture was diluted with 400 milliliters from about 0.005 to about 5.0 parts per 100 parts poly of ice water and extracted 4 times with 400 milliliter mer by weight (Pl-1P) and preferably from about 0.1 to portions of n-pentane. The pentane extracts were comabout 2.0 PHP. When the antioxidants are employed, bined, washed with water, dried over magnesium sulas in the case of polypropylene, they are employed in 20 fate, filtered and concentrated on a rotary evaporator amounts offrom about 0.005 to about 2.5 parts per 100 to give 39.8 grams of a red liquid: b.p. 6668 C at 2.0 parts of the polymer by weight (PHP) and preferably mm pressure; 1R (neat), 1690 (ketone), 1560 (enol) from about 0.02 to about 1.0 Pl-lP. cm; mass spectrum molecular ion m/e 226, also ions The additives are admixed with the polymers utilizing of 170 (M-C H and 101 (S =C -CH C(OH)CH Analysis: Calculated for C H 3F OS: C, 47.9;

Found: C, 48.5; H, 5.3; S, 13.3.

conventional means such as by tumbling powders, solu- 2. Preparation of bis[ 1,1,1-trifluoro-7-methyl-4- tions or slurries of the additives with resin powder or thiolooct-3-en-2-one]nickel(ll). pellets or by more intensive mixing such as in a Nickel acetate tetrahydrate (1 1.0 grams, 0.004 mol) Henschel mixer. The resulting blends are dried, if necin 1 liter of hot absolute ethanol was added to undisessary. and further mixed on a roll mill, Banbury mixer, ill d 1 1 1 ifl 7 h l 4 -3- Brabender Plastograph. extruder and the like to distrib- Lone prepared i part 1 3() grams, ;33 l we the additives in the molten polymers Following tained in 140 milliliters of absolute ethanol with stir- Such mlxillg the resulting blends are normally extruded ring. The resulting dark brown solution was allowed to and pelletlzedcool and stand at 25 0. for20 hours. Water (700 milli- Other additives can be admixed with the compositions such as pigments, dyes, antistatic agents, flllers, processing aids, other stabilizers such as diesters of beta, beta-thiodipropionic acid (i.e. dilaurylthiodipropionate, distearylthiodipropionate, etc.)' and the like providing no antagonistic reaction occurs with the staliters) was added to the solution and the mixture was cooled in an ice bath. Crystals separated and they were filtered off and washed with water to give 23.8 grams of product. Recrystallization from ethanol-water (350150 milliliters) gave 13.2 grams of red-brown nee- Analysis: Calculated for C H 4F 0 S Ni: C, 42.5;

H, 4.76; F, 22.4; S, 12.6; Ni, 11.54.

Found: C, 42.2; H, 4.23; F, 22.3; S, 11.8; Ni, 11.4.-

bilizing additives used in the compositions. dles: m.p. 7677.5C.; IR (KBr), 1550 (C=C), 1530 The advantages of the invention are further illus- (C -'0), 1300, 1200, 817 (C=S)cm-'. trated by the following specific examples.

EXAMPLE ll EXAMPLE I Polypropylene compositions containing ultraviolet 1. Preparation of 1,1,l-trifluoro-7-methyl-4-mercapstabilizers and antioxidants were prepared by blending l0OCt- -2- fl (ketonic form is 1,1,1-trifluoro-7- the stabilizers with molten 3 melt flow (ASTM methyl-4-thioxo-2-oxooctene). i D1238-62T, condition L) polypropylene by means of In a 2-liter, 3-necked, round-bottomed flask, fitted a Brabender Plastograph. To provide processing stabilwith a mechanical stirrer, thermometer and gas disperity during mixing, to. each blend was also added 0.1 php sion tube were placed 37.5 grams (0.178 mol) of 1,1,1- tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocintrifluoro-7-methyl-2,4-octanedione and 1500 milliliters namate)]methane and 0.2 php disteal'yl thiodipropiof absolute ethanol. The flask was cooled in an aceto- 65 onate. The blends were mixed for 5 minutes at 200 C. ne/carbon dioxide bath and hydrogen sulfide was bubunder nitrogen. Samples of 2 mils, 5 mils and 20 mils bled through the stirred solution for 40 minutes, folin thickness were compression molded from each mollowed by dry hydrogen chloride for an additional 40 ten blend. Specimens one-half inch wide and 3 inches long were cut from the molded samples and exposed in a black light/sunlamp device and in a sunshine carbon arc Wcather-Omcter manufactured by Atlas Electric Devices Company. The black light/sunlamp device consists of ten -watt fluorescent sunlamps and ten 20-watt black light fluorescent tubes arranged vertically in a circle in alternate fashion to form a central core. The tubes are about 1 inch apart. A rotatable jacket (no top or bottom) surrounds the core and the samples are mounted on the inside of the jacket so that the distance between samples and lights is about 3 inches.

The specimens are manually flexed daily in a 180. rolling bend test. Failure is indicated by breaking, and time to failure is the average of 5 specimens.

Thermal stability was determined by placing a inch l /z inch specimen cut from each of the 20 mil sheets into a test tube having a hole in the bottom to allow free circulation of air. The tubes were placed in an air oven maintained at 150 C. Failure is recorded as the time in days required to sufficiently embrittle a specimen so that it breaks when it is bent.

6 Table ll Tcnsile UV Hours Strength. Elongation Run Stabilizer on test psi '/1 9 invention 0 3850 41 10 do. 1000 4000 ll do. 2000 4000 l6 12 do. 2750 4000 l2 13 do. 4000 4000 l0 l4 comparison 0 3950 44 l5 do. 1000 4000 30 [6 do. 2000 3750 l0 17 do. 2750 3650 l0 18 do. 4000 3450 X The results show that samples containing the invention ultraviolet stabilizer and the comparison stabilizer have not failed after an exposure time of 2,750 hours. Inspection of the elongation values after 2,750 hours and 4,000 hours show that the invention stabilizer is providing somewhat greater protection than the comparison stabilizer since embrittlement is proceeding at a slower rate.

Those modifications and equivalents which fall- Table I 7 Thermal Hours to Failure stability, BL/SL Weather-Ometer 150 C.. 20 UV stabilizer. php Run 2 mil 5 mil 20 mil 20 mil mil, days control 0 l 99 149 I66 154 49 invention" 01 2 303 523 59 0.2 3 275 822 678 57 0.25 4 704 0.5 5 1696 comparison 0| 6 I41 2M 376 0.2 7 220 349 558 20 0.25 s 365 0.5 9 '492 bis[ 1 .l ,l 'trilluorolmethyl4-thiolooct-3-en-2-o nclnickek ll) (2.2-thiobis-l d t'oclylphenolatolyn-butylamine nickelfll) inspection of the results clearly shows the invention within the spirit of the invention are to be considered stabilizer provides significantly more protection to the 40 a part thereof. polymer than a commercially available nickelh t i l i d i containing ultraviolet stabilizer used as a comparison. 1 A ol l fm Composition h i admixed there. Theinvention stabilizer alsoadds additional thermal with, in an amount to impart thermal and ultraviolet Stability to thefomposmons whereas the comparlsfm light stability to the composition a nickel or cobalt ultraviolet stablllzer adversely affects thermal stability Comlex of a mono or dithiobeta diketone of the of the compositions containing it. mula: z S ll l EXAMPLE Ill 5 wherein Z oxygen or sulfur, An eFhylene/lblutem copolgmeg charactenzed by X fluorine, chlorine, bromine or iodine, and gg gg i "E g g R is a hydrocarbyl radical selected from alkyl, aryl man )an a erlsltyo out and cycloalkyl radicals and combinations thereof g/cc (ASTM Dl505-63T) was mixed with 0.2 php containing from 1 to 18 carbon atoms. 2,6-d1-t-butyl-4-methylphenol as the antioxidant and 2 A d I l h 0.5 php of the ultraviolet stabilizer. The same ultravio- 9 m accor 6 3 w erem let stabilizers were used as in Example II. The blends the Sald Stablhzmg compound 15 present an amount were compression molded into bars mils thick, onefrom about 9- to about Parts by welght Per 100 half inch wide and 6 inches long. The bars were ex- 60 Parts y WelghtPf h p y l posed in a carbon arc Weather-Ometer until failure as A compPsltlon accordance Wlth Claim 1 Wherem recorded in hours occurred. Failure is determined by the polyolefm 1s polyethylene. pulling'each specimen in an lnstron Tester until the ini- 4. A composition in accordance with claim 1 wherein tial tensile strength decreases to about one-third of the the polyolefin is polypropylene. original value or the percent'elongation drops to less 5, A om osition in accordance with claim 4 which than about 10 percent. The results are given in Table ll.

contains heat stabilizing antioxidants.

Patent No. 3 856 750 Dated December 24. 1974 Inventor(s) Jack P. Guillorv and Ronald D. Mathis It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the first page of the patent, second column, in the second I line of the Abstract, after "'violet' insert light Column 4, line 5, after "l,l,l-tribromo-Qthioxo-2-oxoheptane" insert and the like line 40, "25 c." should be 25 C. lines 46-52 should follow line 54. line 53; "(0 6)" should be line 54,

line 54,

"(C 0)" should be In (C'O).

"(0 5)" should be (c- -s Column 5, line 55, "0.2" should be -0.02

what is claimed is: should be WHAT IS CLAIMED Is:

Column 6, line 41,

line 45 "comlex" should be complex Signed and sealed this 8th day of April" 1975.

SEAL) Attest:

C. MARSHALL DANN Commissioner of Patents and Trademarks RUTH '3. I-IASOI E Attesting Officer =ORM PO-IOSO (10-69) 

1. A POLYOLEFIN COMPOSITION HAVING ADMIXED THEREWITH IN AN AMOUNT TO IMPART THERMAL ULTRAVIOLET LIGHT STABILITY TO THE COMPOSITION A NICKEL OR COBALT COMLEX OF A MONO OR DITHIOBETA DIKETONE OF THE FORMULA
 2. A composition in accordance with claim 1 wherein the said stabilizing compound is present in an amount from about 0.005 to about 5.0 parts by weight per 100 parts by weight of the polyolefin.
 3. A composition in accordance with claim 1 wherein the polyolefin is polyethylene.
 4. A composition in accordance with claim 1 wherein the polyolefin is polypropylene.
 5. A composition in accoRdance with claim 4 which contains heat stabilizing antioxidants. 